Cita APA (7th ed.)

COnyango & Tolba Mostafa. (1992). The World environment 1972-1992: Two decades of challenge. Chapman & Hall.

Cita Chicago (17th ed.)

COnyango i Tolba Mostafa. The World Environment 1972-1992: Two Decades of Challenge. London: Chapman & Hall, 1992.

Cita MLA (9th ed.)

COnyango i Tolba Mostafa. The World Environment 1972-1992: Two Decades of Challenge. Chapman & Hall, 1992.